Monday, 24 June 2013

Where does the Day begin?

Dearest Emily,

In November of 1860 dear dear Dodgson gave a lecture at the Ashmolean Society in Oxford;

"Where does the Day begin?" The problem, which was one he was very fond of propounding, may be thus stated: If a man could travel round the world so fast that the sun would be always directly above his head, and if he were to start travelling at midday on Tuesday, then in twenty-four hours he would return to his original point of departure, and would find that the day was now called Wednesday—at what point of his journey would the day change its name? The difficulty of answering this apparently simple question has cast a gloom over many a pleasant party.
Get your head around that one my little one. Actually though- as I recall, it is exactly the sort of puzzle that went on in my little head aged about 9 or 10. I remember quite distinctly pondering stuff like this- and the infinity of the Universe, and what infinity could be imagined as, and how did God work, and was he really real, and what if there was another World War- just because my Dad said there wasn't going to be one- how could he know, and why did Brentford Nylons make horrid brushed nylon fitted sheets in shocking pink that my mother had bought that set my teeth on edge every time a jagged toenail caught it.
All these questions and more crowded my pre-sleep brain, along with a thought about why did we need to learn so much more at school when we knew everything already?
My answers were simple. What I couldn't figure out- I just wasn't meant to understand as a human being. Good cop-out Gail!
Well our Mr Dodgson, clearly never gave up on his night-time questions. They plagued him with insomnia for all of his life. I a mere un-mathematically bent child, solved them by not knowing.
I can see how this puzzle got translated into Through the Looking Glass, with the Red Queen and Alice running as fast as they could and ending up in the same place.

Today, I was back in the lovely Bookroom, and reading 'The Illustrated London News', from 1859. There were lots of interesting snippets, which I'll save for another time- but today, I'll show you this one- it is for June 25th (ie tomorrow) a hundred and fifty years ago- and all about the weather...

Look Em,

It says, on the longest day (just as we had last week) the sun rose at 15 minutes past three a.m, and set at 47 minutes past eight p.m. The length of the day was consequently 17 hours 32 minutes.

15 minutes past three a.m sunrise Emily! Goodness moi. As you know, GiGi faces the sunrise in her bedroom, and has found it easier to change her working day to fit in with natural day-light hours, at least in the summer- but for me at least, this doesn't even begin to wake me until about five-thirty. Plus, they didn't have 'British Summer Time', but even so-Em, what with the clock being a bit here and there all over the Country, no wonder our Dodgson, ever the Railway Journey Afficionado got all hung up on time.

Well, when he was down here, he can't have slept much. Liking to work until the wee small hours- unless he invented some light-blocking cleverness, he would have been up with the sunrise, just about when he went to sleep!

No wonder he got a bit cranky Em,

Off to bed for you now my little girl,

Your ever-loving Grand-Mother, GiGi xxx


  1. Well, as you now know Gail, the answer was to create an arbitrary line from pole to pole on which the day is accepted as changing globally (so to speak); the day also changes locally (so to speak) at midnight: so between midnight and the International Dateline it is today on one side and tomorrow on the other (or yesterday and today, depending on what time it is where you are); and just for one infinitesimal instant when it's midnight on the dateline, it's today all over the world. Simples!

  2. ... of course, the International Dateline isn't actually a STRAIGHT line: it goes around some islands a little earlier or later, to avoid the awkwardness of it being today over this side of the island and tomorrow (or yesterday) on the other. If this is a little tricky to understand, just go back to being blissfully ignorant like I do!

  3. Exactemente Steve, interesting, good to ponder, wonder and then give up!

  4. The mental exercise is good for the brain; and, as everyone knows, it's better to travel hopefully than to arrive.

  5. Travelling hopefully is my life-tag!